is there a way to get the available computer's memory? Or preferably what's free? I've come across this in the docs "GeMemGetFreePhysicalMemoryEstimate()" but it's returning a negative value. Is this correct?

Just on another note, how can one calculate the memory space required for a bitmap? For instance, a 1920x1080 at 32B - if I know the resolution etc, how can I calculate the memory that image takes up?